Russell Kauffman has been in this industry for as long as I can remember; he has worked for Bowers & Wilkins, Morel, and was a regular on Paul Messenger’s legendary blind listening tests in the 1990s. But his role has generally been in sales and marketing, so it was with some surprise that I discovered the Russell K brand back in 2014. It seems that while in those meetings with engineers Russell was quietly absorbing a lot of what it takes to build a loudspeaker. He mentions Epos founder Robin Marshall as one person who liked to talk tech, and that must have been a good set of conversations because the reviews that have greeted Russell K’s Red series of loudspeakers have been enthusiastic all round. I have to admit I was intrigued; what did these fairly diminutive and apparently undamped speakers do that made them so popular?
The Red 120 is the latest member of a small range that includes two stand-mounts, the Red 50 with a 130mm mid/bass driver, and Red 100 with a 165mm driver. There are as many floorstanders that look like the stand-mounts, but with an extra main driver and a bigger box. The Red 120 is the smaller of the two and combines a 25mm soft-dome tweeter with 130mm cones in a two-and-a-half-way configuration, meaning that the top cone does bass and midrange while the bottom one covers only the lower octaves, like many others.
The main difference lies inside the cabinet where there is no damping, something that would usually result in a very lively and coloured sounding loudspeaker, and not the sort of thing to garner a lot of praise. But instead of damping, Russell uses shelf braces with holes in below each of the drivers. Each shelf has a different number of holes that have been determined by extensive acoustic tuning. The idea is to trap the midrange within a small section of the cabinet – to provide a damping brake around 100Hz – then allow the whole system to relax for the lower bass. There is a vertical tube going through a solid brace just above the visible port, but it does not bend round to the outlet, instead venting in to small internal space. It’s a unique arrangement to my knowledge and must be key to the vitality that this small speaker can find in a recording.